Pressure transducers are employed for measuring the combustion dynamics in an internal combustion engine. Such transducers are referred to as combustion transducers. The transducer desirably should be of a small size and have the capability of performing static and dynamic measurements. The transducer should have a high natural frequency for fast data rates and be extremely durable for the typical combustion engine environment.
As one can ascertain, a combustion engine is an extremely reliable device which can operate under relatively high temperatures in very different environments. The Assignee herein, namely, Kulite Semiconductor Products, Inc. has a number of patents which involve a technology referred to as silicon on insulator (SOI) leadless technology. These sensors are capable of withstanding harsh environments, extreme operating temperatures in excess, for example of 600° C. and high vibrations.
As will be described the device employed herein utilizes an innovative transducer design employing a vibration insensitive sensing element. This transducer employs two diaphragms with one exposed to pressure and inertial forces and the other exposed only to inertial forces. Each diaphragm is associated with a half bridge which half bridges are wired into a full bridge employing differential action where inertial forces are cancelled.
The Assignee, namely, Kulite Semiconductor Products has various patents as well as pending applications which show transducer arrangements.
It is understood that a major aspect of the present invention is the use of a pressure restrictor which can be changed according to environment and which is simple to fabricate and operates with great efficiency.